Dependable's keel was laid down by the American Ship Building Company, Lorain, Ohio on July 17, 1967 and she was launched March 16, 1968.

She was designed for search-and-rescue work; at launch, she had a small, high superstructure with 360-degree visibility and a correspondingly large helicopter pad aft without a hanger.

In January 1992, the ship and her crew relocated to Galveston, Texas[3] where she remained until she was decommissioned on February 24, 1995 for Major Maintenance Availability, an 18-month, 21.7 million dollar project at the United States Coast Guard Yard in Baltimore, Maryland, to overhaul and upgrade selected systems and equipment.

[3] Examples of Dependable's missions throughout her working life include enforcing fishery regulations in the Atlantic, interdicting drug traffickers in the Caribbean, and rescuing Cuban and Haitian migrants in the Florida Straits.

In 1978, Dependable's third year of conducting law enforcement patrols, the crew intercepted and interdicted 15% of the marijuana seized by the entire Coast Guard.

The largest seizure of 1978 was on August 7 when she seized the merchant vessel Heidi, which was carrying over 240,000 lb (110,000 kg) of marijuana.

At the very end of her active service, during a December 2023-February 2024 patrol supporting Operation Vigilant Sentry, Dependable searched for and found a 25-foot vessel in distress off the coast of Haiti.

Working in 8- to 12-foot seas and winds gusting to 46 mph, Dependable's crew rescued all 33 people aboard the distressed vessel.